Fails to boot old image from U-Boot on IMX8

While testing and evaluating the BaelnaOS & BalenaCloud on our iot-gate-imx8, Flashed the latest image to the iot-gate-imx8, which was great and impresive. now when trying to go back to old Compulab Image, with USB Flash drive. it is not booted or recongized o U-Boot, also cannot stop the boot process on U-Boot as it was before.
What am i missing here? how can i bring it back to previous OS without running the Recovery process?
Thanks & BR
Yakov Avshalom